JP4325515B2 - Cup-shaped part molding method and molding apparatus - Google Patents

Description

  The present invention relates to a molding method and a molding apparatus for a cup-shaped part having a bottom surface portion and an annular side wall portion erected in the axial direction from an outer peripheral end portion of the bottom surface portion.

Conventionally, a cup-shaped part having a bottom surface portion and an annular side wall portion standing from the outer peripheral end portion of the bottom surface portion is formed by press molding.
In particular, as shown in FIG. 13 (d), the annular side wall portion has an annular small diameter side wall portion 92 positioned on the bottom surface portion 91 side, and a large diameter side wall whose diameter is larger than that of the small diameter side wall portion 92 via the stepped portion 93. In the case of having a stepped side wall shape provided with the portion 94, there is a possibility that the material portion is insufficient in the small-diameter side wall portion 92 and a sink mark (thin wall portion) or the like is partially generated. Thus, the cup-shaped part 9 is formed.

  That is, first, as shown in FIG. 13A, the central portion of the flat plate material 90A as the work 90 is drawn, and a part of the flat plate material 90A is depressed, so that the bottom surface portion 91 and the spare small-diameter side wall portion 96 are formed. And form. Further, the auxiliary small-diameter side wall portion 96 is formed to have an outer diameter larger than the outer diameter of the target small-diameter side wall portion 92 and narrowed deeper than the target small-diameter side wall portion 92. Next, as shown in FIG. 13B, the preliminary small-diameter side wall portion 96 of the workpiece 90 is subjected to reduced diameter molding for reducing the outer diameter and compression molding for reducing the depth, and the target outer diameter and the target depth. A small-diameter side wall portion 92 is formed. At this time, the small-diameter side wall portion 92 is formed so as to return the thickness of the preliminary small-diameter side wall portion 96, which has been thinned by the above-described drawing, to the original thickness of the flat plate material 90A.

Next, as shown in FIG. 13C, drawing and upsetting are performed on the outer peripheral side portion of the work 90 to form the stepped portion 93 and the preliminary large-diameter side wall portion 97. Thereafter, as shown in FIG. 13 (d), the preliminary large-diameter side wall 97 of the work 90 is ironed to form a large-diameter side wall 94 having a target depth, and the cup-shaped part 9 is molded. Yes.
In this manner, an extra material portion for forming the small-diameter side wall portion 92 is secured in the preliminary small-diameter side wall portion 96, and thereafter, the pre-small-diameter side wall portion 96 is subjected to diameter reduction molding and compression molding to obtain a small-diameter side wall portion having a target depth. By molding 92, the thickness of the small-diameter side wall portion 92 is secured, and in this small-diameter side wall portion 92, occurrence of sink marks and the like due to insufficient thickness of the material portion is suppressed.

  However, when performing each molding, a transfer press apparatus including a plurality of molding press apparatuses is prepared, and each molding is performed by sequentially transferring the workpiece 90 to each molding press apparatus by transfer. Therefore, the equipment capacity of the transfer press device for molding the cup-shaped part 9 is the sum of the required loads in a plurality of molding press processes, so that a very large equipment capacity is required, and the entire equipment is enlarged. . Such a problem is the same in the case where a plurality of single molding presses operating independently are arranged to perform each molding.

  Further, as described above, the thickness of the conventional small-diameter side wall portion 92 is ensured by forming the auxiliary small-diameter side wall portion 96 having an outer diameter larger than that of the small-diameter side wall portion 92 and a depth deeper than that of the small-diameter side wall portion 92. Is done by doing. That is, the preliminary small-diameter side wall portion 96 is erected perpendicularly to the surface of the flat plate material 90A so as to be deeper than the target depth, and the thickness is significantly smaller than the target thickness. Then, by performing the above-mentioned diameter reduction molding and compression molding, it is necessary to return the greatly reduced thickness to the original thickness, and it is difficult to secure a sufficiently thick material portion in the small diameter side wall portion 92. .

  Further, for example, in the cup forming method of Patent Document 1, a method is disclosed in which a plurality of forming portions are operated to form a cup (cup-shaped part 9) having a desired shape with a single double-acting press. However, in patent document 1, the cup-shaped component 9 which has the said step side wall shape is not shape | molded, and the technique which ensures the thickness in the small diameter side wall part 92 is not disclosed at all.

JP 2000-254736 A

  The present invention has been made in view of such conventional problems, and can reduce the size of molding equipment and can mold cup-shaped parts having stepped side wall shapes with excellent strength and dimensional accuracy. It is an object of the present invention to provide a method and apparatus for forming a cup-shaped part.

The first invention includes a bottom surface portion, an annular small-diameter side wall portion erected from an outer peripheral end portion of the bottom surface portion, and an annular step portion formed outward from the end portion of the small-diameter side wall portion, In a method of molding a cup-shaped part having an annular large-diameter side wall portion standing from the outer peripheral end portion of the stepped portion,
Preliminary molding to obtain a preformed body by drawing a flat plate material, and forming a preliminary bottom surface portion having an outer diameter smaller than the bottom surface portion and a preliminary inclined side wall portion inclined in an annular manner from the preliminary bottom surface portion. Process,
Forming the preformed body, forming the bottom surface portion from the base end side portion of the preliminary inclined side wall portion and the preliminary bottom surface portion, and forming the preliminary large-diameter side wall portion from the distal end side portion of the preliminary inclined side wall portion. Forming and forming the small-diameter side wall portion and the stepped portion from an intermediate portion between the base end portion and the tip end portion to obtain an intermediate formed body; and
A cup-shaped part molding method comprising: finishing molding the preformed large-diameter side wall part to form the large-diameter side wall part to obtain the cup-shaped part. 1).

The cup-shaped component molding method of the present invention is to mold a cup-shaped component having a stepped side wall shape including a small diameter side wall portion, a stepped portion and a large diameter side wall portion. In this molding method, before forming the target small-diameter side wall portion, the preliminary small-diameter side wall portion inclined in an annular shape is once molded to suppress the occurrence of sink marks or the like in the small-diameter side wall portion. Is molded.
That is, in the present invention, in the pre-forming step, pre-forming having a pre-bottom bottom surface portion having an outer diameter smaller than the bottom surface portion of the cup-shaped part to be formed and a pre-inclined side wall portion that is inclined in an annular shape from now on. Shape the body. The preliminary inclined side wall portion is formed by drawing until substantially the entire material portion on the outer peripheral side of the preliminary bottom surface portion is inclined and erected. Therefore, it can suppress that the thickness of a preliminary | backup inclination side wall part becomes thin thinly.

In the intermediate forming step, the bottom surface portion of the cup-shaped component is formed from a part of the preliminary inclined side wall portion and the preliminary bottom surface portion, and the small-diameter side wall portion of the cup-shaped component from the other part of the preliminary inclined side wall portion and A step portion is formed. Further, a preliminary large-diameter side wall portion is formed from the remaining portion of the preliminary inclined side wall portion.
Therefore, the small-diameter side wall portion can be formed by supplying the material portion from the pre-inclined side wall portion in which the thinning is suppressed, and the thickness in the small-diameter side wall portion can be sufficiently ensured.

Thereafter, in the finish forming step, the preliminary large-diameter side wall portion is ironed to form a cup-shaped part having a bottom surface portion, a small-diameter side wall portion, a step portion, and a large-diameter side wall portion.
Therefore, according to the present invention, it is possible to suppress the occurrence of sink marks or the like in the small-diameter side wall portion of the cup-shaped component, and it is possible to mold a cup-shaped component having a stepped sidewall shape with excellent strength and dimensional accuracy. .

Further, in the present invention, when the cup-shaped part is molded, the cup-shaped part having a stepped side wall shape can be formed by performing a small number of molding steps without requiring compression molding.
Therefore, each molding process can be performed by one molding press apparatus, instead of sequentially performing each molding process by a transfer press apparatus having a plurality of molding press apparatuses. Therefore, the equipment capability of the molding press apparatus that performs each molding process can be a required load of the molding process with the largest load in each molding process, and the molding equipment can be downsized.
Therefore, according to the method for molding a cup-shaped part of the present invention, it is possible to reduce the size of the molding equipment and to mold a cup-shaped part having a stepped side wall shape with excellent strength and dimensional accuracy.

The second invention includes a bottom surface portion, an annular small-diameter side wall portion erected from the outer peripheral end portion of the bottom surface portion, an annular step portion formed outward from the end portion of the small-diameter side wall portion, In a molding apparatus for molding a cup-shaped part having an annular large-diameter side wall portion erected from the outer peripheral end portion of the stepped portion,
The molding apparatus includes a die having a molding hole, and a first punch and a second punch that are arranged to face each other so as to slide in the molding hole of the die.
The first punch is divided into a punch outer peripheral portion and a punch core portion positioned substantially at the center thereof, and the punch outer peripheral portion forms a part of the bottom surface portion, the small-diameter side wall portion, and the step portion. The punch core portion has a flat pressure surface for forming the remainder of the bottom surface portion, and the outer diameter of the flat pressure surface is outside the bottom surface portion. Smaller than the diameter,
The second punch has a convex annular facing surface having a shape along a shape when a part of the stepped annular pressure surface in the outer peripheral portion of the punch and the flat pressure surface in the punch core portion form substantially the same surface. Has
The molding apparatus advances the punch core portion in the first punch relative to the die, and then advances the punch outer peripheral portion in the first punch relative to the die and the second punch, and then The cup-shaped component molding apparatus is configured to advance the punch outer peripheral portion and the second punch in the first punch with respect to a die.

In the cup-shaped part molding apparatus of the present invention, a device for molding the cup-shaped part having the stepped side wall shape while suppressing the occurrence of sink marks or the like in the small-diameter side wall part is made.
That is, in the molding apparatus of the present invention, the first punch and the second punch that slide in the molding hole of the die are devised. The first punch is divided into a punch outer peripheral portion and a punch core portion, and these can be advanced separately.

Further, the stepped annular pressure surface is formed on the outer peripheral portion of the punch, the flat pressure surface is formed on the punch core portion, and the convex annular facing surface is formed on the second punch.
In this way, the molding apparatus is configured to advance the punch outer peripheral portion after the punch core portion is advanced, and then advance the punch outer peripheral portion and the second punch, and thus has excellent strength and dimensional accuracy as follows. A cup-shaped part can be formed efficiently.

  That is, in forming the cup-shaped part, first, a flat plate material as a workpiece is disposed between the first punch, the die, and the second punch, and the punch core portion is advanced with respect to the die. At this time, the flat plate material is pressed by a flat pressure surface whose center side portion is smaller than the outer diameter of the bottom surface portion of the cup-shaped part to be molded in a state where the outer peripheral side portion is in contact with the die. .

As a result, a preliminary bottom surface portion having an outer diameter smaller than that of the bottom surface portion is formed from the center side portion, and a preliminary inclined side wall portion inclined in an annular manner from the preliminary bottom surface portion is formed from the outer peripheral side portion.
Therefore, the preliminary inclined side wall portion is only drawn until the entire material portion on the outer peripheral side of the preliminary bottom surface portion is inclined upright, and the thickness of the preliminary inclined side wall portion is significantly reduced. Can be suppressed. Further, when the punch core portion is formed, the preliminary bottom surface portion of the workpiece is sandwiched between the punch core portion and the second punch.

Next, the outer peripheral portion of the punch is advanced with respect to the die and the second punch while maintaining the state where the preliminary bottom surface portion of the workpiece is sandwiched.
At this time, the pre-inclined side wall portion is pressed so that the stepped annular pressure surface in the outer peripheral portion of the punch sandwiches the pre-inclined side wall portion between the convex annular facing surface in the second punch. As a result, the preliminary inclined side wall portion is deformed along the shapes of the stepped annular pressure surface and the convex annular opposing surface, and the bottom surface portion of the cup-shaped part is formed from a part of the preliminary inclined side wall portion and the preliminary bottom surface portion. The small-diameter side wall portion and the step portion of the cup-shaped part are formed from the other part of the preliminary inclined side wall portion, and the annular preliminary large-diameter side wall portion is formed from the remaining portion.

  Therefore, the small-diameter side wall portion can be formed by supplying the material portion from the pre-inclined side wall portion in which the thinning is suppressed, and the thickness in the small-diameter side wall portion can be sufficiently ensured. Further, when forming by the punch outer peripheral portion, the step portion of the work is sandwiched between the punch outer peripheral portion and the second punch.

Then, the state which clamped the level | step-difference part of the said workpiece | work is maintained, and a punch outer peripheral part and a 2nd punch are advanced with respect to die | dye.
At this time, the preliminary large-diameter side wall portion is ironed by the die and the outer peripheral portion of the punch to form the large-diameter side wall portion of the cup-shaped part.

Thus, by using the molding apparatus of the present invention, it is possible to suppress the occurrence of sink marks or the like in the small-diameter side wall portion of the cup-shaped component, and it is possible to mold a cup-shaped component having excellent strength and dimensional accuracy. Further, the molding apparatus of the present invention has the die, the first punch, and the second punch having the above-described configuration, and the cup-shaped part having the above-described stepped side wall shape can be molded only by the molding device having the above-described configuration.
Therefore, by employing the cup-shaped part molding apparatus of the present invention, it is possible to reduce the size of the molding equipment (apparatus) and to mold a cup-shaped part having excellent strength and dimensional accuracy.

A preferred embodiment in the first and second inventions described above will be described.
In the first aspect of the invention, in the finish forming step, it is preferable that iron molding is performed on the preliminary large-diameter side wall portion and tooth molding is performed, and a tooth surface is formed on the large-diameter side wall portion. 2).
In this case, the occurrence of sink marks or the like in the small-diameter side wall portion can be suppressed, and a cup-shaped part having a tooth surface on the large-diameter side wall portion can be ensured in strength and molded with high dimensional accuracy.

The cup-shaped component is preferably a clutch drum having a tooth surface on the large-diameter side wall (Claim 3).
In this case, the occurrence of sink marks or the like in the small-diameter side wall portion can be suppressed, and the clutch drum can be formed with sufficient strength and with high dimensional accuracy.
The clutch drum may be a power transmission component such as a transmission.

  In forming the cup-shaped part, a die having a forming hole and a first punch and a second punch arranged to face each other so as to slide in the forming hole of the die are prepared. The first punch is divided and formed into a punch outer peripheral portion and a punch core portion positioned substantially at the center thereof, the flat plate material is disposed between the first punch, the die and the second punch, Advance the punch core portion in the first punch relative to the die, perform the preforming step, and then maintain the state of sandwiching the preform between the punch core portion and the second punch, The punch outer periphery of the first punch is advanced with respect to the die and the second punch to perform the intermediate forming step, and then the punch outer periphery and the second pan Maintaining a state of sandwiching the above intermediate form between, with respect to the die by advancing the punch outer peripheral portion and the second punch, it is preferable to perform the finish forming process (claim 4).

In this case, a cup-shaped part having excellent strength and dimensional accuracy can be molded by one molding press apparatus using the die, the first punch, and the second punch.
And after shaping | molding the said preforming body in a preforming process, this preforming body is clamped between a punch core part and a 2nd punch, and this clamping state is maintained, and the said intermediate molding body is carried out in an intermediate molding process. Is molded. Further, after the intermediate formed body is formed, the intermediate formed body is sandwiched between the outer peripheral portion of the punch and the second punch, and this sandwiched state is maintained, and the cup-shaped part is formed in the finish forming step. .
Therefore, the cup-shaped part can be molded in a state where the preform and the intermediate molded body are sandwiched between the first punch and the second punch, and each molding step can be performed continuously. Therefore, the cup-shaped part having excellent strength and dimensional accuracy can be molded in a short time.

  In the second aspect of the invention, a die side tooth mold forming surface for forming a tooth surface on the large-diameter side wall portion is formed on the inner wall surface of the forming hole in the die. It is preferable that a punch side tooth mold forming surface for forming a tooth surface on the large diameter side wall portion is formed on the outer peripheral surface of the punch outer peripheral portion of the punch together with the die side tooth mold forming surface. 6).

  In this case, when the large-diameter side wall portion is formed by advancing the punch outer peripheral portion and the second punch in the first punch with respect to the die, the die side tooth mold forming surface formed on the die is formed. And a tooth surface can be formed in a large diameter side wall part by the punch side tooth-molding surface formed in the punch outer peripheral part. Therefore, generation | occurrence | production of the sink etc. in the said small diameter side wall part can be suppressed, intensity | strength can be ensured and a cup-shaped component provided with the tooth surface in the large diameter side wall part can be shape | molded with a sufficient dimensional accuracy.

Hereinafter, embodiments of the cup-shaped part molding method and molding apparatus according to the present invention will be described with reference to the drawings.
As shown in FIGS. 1 to 6, the cup-shaped part molding apparatus 1 (hereinafter simply referred to as the molding apparatus 1) of the present example has a bottom surface portion 81 and an annular shape standing from the outer peripheral end portion of the bottom surface portion 81. A small-diameter side wall portion 82, an annular stepped portion 83 formed outward from the end portion of the small-diameter side wall portion 82, and an annular large-diameter side wall portion 84 erected from the outer peripheral end portion of the stepped portion 83. The cup-shaped component 8 having the above is formed.

As shown in FIGS. 7 and 11, the molding apparatus 1 includes a die 2 provided with a molding hole 21, and a first punch 3 and a second punch 2 arranged to face each other so as to slide in the molding hole 21 of the die 2. And a punch 6.
The first punch 3 is divided and formed into a punch outer peripheral portion 5 and a punch core portion 4 located substantially at the center thereof. The punch outer peripheral portion 5 includes a stepped annular pressure surface 51 for forming a part of the bottom surface portion 81 of the cup-shaped part 8, the small-diameter side wall portion 82, and the stepped portion 83. A flat pressure surface 41 for forming the remaining portion of the portion 81 is provided. The outer diameter of the flat pressure surface 41 is smaller than the outer diameter of the bottom surface portion 81.

Further, as shown in FIGS. 7 and 11, the second punch 6 is formed when a part of the stepped annular pressure surface 51 in the punch outer peripheral portion 5 and the flat pressure surface 41 in the punch core portion 4 form substantially the same surface. The convex annular facing surface 61 having a shape along the shape is provided.
Further, on the inner wall surface of the forming hole 21 in the die 2, a die side tooth mold forming surface 22 for forming a tooth surface on the large-diameter side wall portion 84 of the cup-shaped component 8 is formed. Further, on the outer peripheral surface of the punch outer peripheral portion 5 in the first punch 3, a punch side tooth mold forming surface 52 for forming a tooth surface on the large diameter side wall portion 84 is formed together with the die side tooth mold forming surface 22. Yes.

The molding apparatus 1 advances the punch core portion 4 of the first punch 3 with respect to the die 2 as shown in FIGS. 4 and 8, and then the die 2 and the second as shown in FIGS. 5 and 9. The punch outer peripheral portion 5 in the first punch 3 is advanced with respect to the punch 6, and then the punch outer peripheral portion 5 and the second punch 6 in the first punch 3 are advanced with respect to the die 2 as shown in FIGS. 6 and 11. It is configured to let you. And the shaping | molding apparatus 1 can advance the punch core part 4, the punch outer peripheral part 5, and the 2nd punch 6 independently, and shape | molds the cup-shaped component 8 by performing several shaping | molding to the flat plate raw material 80A. It constitutes a double-acting press that can.
This will be described in detail below.

  In this example, as shown in FIG. 3 to FIG. 6 and FIG. 7 to FIG. 11, the first punch 3 and the second punch 6 are moved downward in the forming hole 21 of the die 2 to perform forming. Has been. The first punch 3 is located above the second punch 6, and the advancement of the punch core portion 4, the punch outer peripheral portion 5, or the second punch 6 moves downward with respect to the die 2. Say.

  As shown in FIGS. 7 and 12, the stepped annular pressure surface 51 in the punch outer peripheral portion 5 is formed at the tip of the punch outer peripheral portion 5, and the outer peripheral pressure surface portion 513 located on the outer peripheral side, It has an inner peripheral pressure surface portion 511 that protrudes more distally than the outer peripheral pressure surface portion 513 and is formed in a substantially flat shape. Further, an intermediate pressure surface portion 512 is formed between the outer peripheral pressure surface portion 513 and the inner peripheral pressure surface portion 511 toward the axial direction L of the first punch 3 and the second punch 6.

  Further, as shown in FIGS. 7 and 12, the convex annular facing surface 61 of the second punch 6 is formed at the tip of the second punch 6, and is opposed to the outer peripheral side facing the outer peripheral pressure surface 513. A surface portion 613 and an inner peripheral facing surface portion 611 facing the inner peripheral pressure surface portion 511 are provided. Further, an intermediate facing surface portion 612 is formed between the outer peripheral facing surface portion 613 and the inner peripheral facing surface portion 611 toward the axial direction L of the first punch 3 and the second punch 6.

As shown in FIG. 7, the flat plate material 80A is formed in a disc shape and has a through hole 800 at the center thereof. At least one of the punch core portion 4 and the second punch 6 in the first punch 3 is formed with a positioning portion 7 that engages with the through hole 800 and positions the flat plate material 80A.
In this example, the protruding pin 62 that can be inserted and arranged in the through hole 800 is formed on the convex annular facing surface 61 of the second punch 6, and the protruding pin 62 can be inserted and arranged on the flat pressure surface 41 of the punch core portion 4. A pin insertion recess 42 is formed.

As shown in FIGS. 1 and 2, the cup-shaped component 8 to be molded in this example is a clutch drum 8 having a tooth surface on the large-diameter side wall portion 84 and used for a transmission. The tooth surface of the large-diameter side wall portion 84 has a material portion having a predetermined width, and has irregularities formed alternately on the inner peripheral side and the outer peripheral side of the large-diameter side wall portion 84.
The molding apparatus 1 of the present example is a hydraulic molding apparatus 1 that molds the cup-shaped component 8 by hydraulic pressure. And the punch core part 4 and the punch outer peripheral part 5 in the 1st punch 3, and the 2nd punch 6 operate | move under the pressurization force by hydraulic pressure.

In this example, by using one molding apparatus 1 having the above-described configuration, the following molding steps are performed to mold a cup-shaped component 8 having a stepped side wall shape.
In forming this cup-shaped part 8, as shown in FIGS. 3 and 7, first, as a pre-forming step, a flat plate material 80A as a work 80 is placed between the first punch 3 and the die 2 and the second punch 6. To place. Further, in the first punch 3, the flat pressure surface 41 of the punch core portion 4 is protruded from the stepped annular pressure surface 51 of the punch outer peripheral portion 5.

Then, as shown in FIGS. 4 and 8, the first punch 3 in a state in which the punch core portion 4 protrudes from the punch outer peripheral portion 5 is advanced with respect to the die 2.
At this time, the flat plate material 80A has a flat pressing surface 41 whose center side portion is smaller than the outer diameter of the bottom surface portion 81 of the cup-shaped component 8 to be molded in a state where the outer peripheral side portion is caught by the die 2. Pressurized. Then, the outer peripheral side portion of the flat plate material 80A is drawn into an inclined shape, and the protruding pin 62 in the second punch 6 is inserted into the through hole 800 of the workpiece 80 and inserted into the pin insertion recess 42 in the punch core portion 4. .

  Further, the outer peripheral end portion of the outer peripheral portion of the workpiece 80 is sandwiched between the tip end portion of the punch-side tooth mold forming surface 52 in the punch outer peripheral portion 5 and the upper opening end portion of the forming hole 21 in the die 2. In a state where the corners of the inner peripheral pressure surface portion 511 in the outer peripheral part 5 press the outer peripheral part of the work 80, the outer peripheral part of the work 80 is drawn into an inclined shape.

As a result, a preliminary bottom surface portion 85 having an outer diameter smaller than that of the bottom surface portion 81 is formed from the center side portion, and a preliminary inclined side wall portion 86 that is inclined in an annular shape from the preliminary bottom surface portion 85 is formed from the outer peripheral side portion. The And the preforming body 80B which has the preliminary | backup bottom face part 85 and the preliminary | backup inclination side wall part 86 is shape | molded.
In this way, the preliminary inclined side wall portion 86 is only drawn until almost the entire material portion on the outer peripheral side of the preliminary bottom surface portion 85 is inclined and erected, and the preliminary inclined side wall portion 86 is formed on the opening side. It is only drawn until it is tilted up so that its diameter increases. Therefore, the tensile load applied to the preliminary inclined side wall portion 86 can be kept small, and the thickness of the preliminary inclined side wall portion 86 can be suppressed from being significantly reduced.

Further, as shown in FIG. 8, when the preform 80 </ b> B as the work 80 is formed, the preform 80 </ b> B is formed with respect to the first punch 3 and the second punch 6 by the protruding pin 62 in the second punch 6. In this state, the preliminary bottom surface portion 85 is sandwiched between the punch core portion 4 and the second punch 6.
As shown in FIG. 12, the preliminary inclined side wall portion 86 is preferably drawn to a state where the outer angle (outside angle) formed with respect to the preliminary bottom surface portion 85 has an inclination angle θ of 30 to 50 °. .

Next, as shown in FIGS. 5 and 9, as an intermediate forming step, the preliminary bottom surface portion 85 of the preform 80 </ b> B is sandwiched between the punch core portion 4 and the second punch 6, and the punch outer peripheral portion 5 and the die are formed. 2, the outer peripheral end portion of the preform 80 </ b> B is held, and the punch outer peripheral portion 5 of the first punch 3 is advanced with respect to the die 2 and the second punch 6.
At this time, the preliminary inclined side wall portion 86 is pressurized such that the stepped annular pressure surface 51 in the punch outer peripheral portion 5 is sandwiched between the convex annular facing surface 61 in the second punch 6. Thereby, the preliminary | backup inclination side wall part 86 deform | transforms along the shape of the stepped annular pressure surface 51 and the convex annular opposing surface 61. FIG.

  That is, as shown in FIG. 12, the proximal end side portion 861 of the preliminary inclined side wall portion 86 is directed toward the inner peripheral side facing surface portion 611 of the convex annular facing surface 61 by the inner peripheral pressure surface portion 511 of the stepped annular pressing surface 51. The inclined diaphragm deformation is returned to the flat shape again so as to form the same plane as the preliminary bottom surface portion 85. Further, an intermediate portion 862 located between the base end side portion 861 and the tip end side portion 863 of the preliminary inclined side wall portion 86 is arranged on the outer periphery of the convex annular facing surface 61 by the outer peripheral pressure surface portion 513 of the stepped annular pressure surface 51. Pressure is applied toward the side facing surface portion 613, and the inclined diaphragm deformation is returned to a state close to a planar shape.

As a result, a part of the material portion in the proximal end portion 861 of the preliminary inclined side wall portion 86 is formed in the gap between the intermediate pressure surface portion 512 of the stepped annular pressure surface 51 and the intermediate facing surface portion 612 of the convex annular facing surface 61. Is supplied from the inner peripheral side. Further, a part of the material portion in the intermediate portion 862 of the preliminary inclined side wall portion 86 is also supplied to the gap from the outer peripheral side.
Therefore, when the small-diameter side wall portion 82 of the cup-shaped part 8 is formed in the gap between the intermediate pressure surface portion 512 of the stepped annular pressure surface 51 and the intermediate facing surface portion 612 of the convex annular facing surface 61, the small-diameter side wall is formed. A sufficient amount of material portion can be supplied to the portion 82. Further, the small-diameter side wall portion 82 can be formed by supplying a material portion from the preliminary inclined side wall portion 86 in which the thinning is suppressed as described above.

Therefore, in the formed small diameter side wall part 82, it can prevent that a raw material part runs short, and the thickness in the small diameter side wall part 82 can fully be ensured.
Thus, the bottom surface portion 81 of the cup-shaped component 8 is formed from the base end side portion 861 and the preliminary bottom surface portion 85 of the preliminary inclined side wall portion 86, and the preliminary large diameter side wall portion 87 is formed from the distal end side portion 863 of the preliminary inclined side wall portion 86. The small-diameter side wall portion 82 and the stepped portion 83 are formed from the intermediate portion 862 of the preliminary inclined side wall portion 86. Then, an intermediate molded body 80 </ b> C having the bottom surface portion 81, the small diameter side wall portion 82, the stepped portion 83, and the preliminary large diameter side wall portion 87 is formed.
As shown in FIG. 9, when the intermediate formed body 80 </ b> C is formed, the intermediate formed body 80 </ b> C has the bottom surface portion 81 sandwiched between the punch core portion 4 and the second punch 6, and the small-diameter side wall portion 82. And the step part 83 is clamped between the punch outer peripheral part 5 and the second punch 6.

  Next, as shown in FIGS. 6, 10, and 11, as a finish forming step, the bottom portion 81 and the small-diameter side wall portion 82 of the intermediate formed body 80 </ b> C are provided between the punch core portion 4 and the punch outer peripheral portion 5 and the second punch 6. The first punch 3 (punch core portion 4 and punch outer peripheral portion 5) and the second punch 6 are advanced together with respect to the die 2 while maintaining the state where the step portion 83 is sandwiched.

At this time, iron forming and tooth forming are performed on the preliminary large-diameter side wall portion 87 of the intermediate formed body 80C by the die side tooth mold forming surface 22 of the die 2 and the punch side tooth mold forming surface 52 of the punch outer peripheral portion 5. A large-diameter side wall portion 84 having a tooth surface is formed. And the cup-shaped component 8 which has the bottom face part 81, the small diameter side wall part 82, the level | step-difference part 83, and the large diameter side wall part 84 can be shape | molded.
FIG. 10 shows the molding apparatus 1 in a state before performing ironing and tooth molding, and FIG. 11 shows the molding apparatus 1 in a state after performing ironing and tooth molding.

As described above, according to this example, it is possible to sufficiently ensure the thickness of the small-diameter side wall portion 82 and to suppress the occurrence of sink marks or the like in the small-diameter side wall portion 82 of the cup-shaped component 8. Therefore, the cup-shaped component 8 having a stepped side wall shape with excellent strength and dimensional accuracy can be formed.
Further, the cup-shaped component 8 can be molded in a state where the preform 80B and the intermediate molded body 80C are sandwiched between the first punch 3 and the second punch 6, and each molding step is performed continuously. be able to. Therefore, the cup-shaped component 8 excellent in strength and dimensional accuracy can be molded in a short time.

Further, in this example, when the cup-shaped part 8 is molded, compression molding is not required, and the cup-shaped part 8 having the stepped side wall shape by the small-diameter side wall part 82 and the stepped part 83 is obtained by performing a small molding process. Can be molded.
Therefore, each molding process can be performed by one molding apparatus 1 instead of sequentially performing each molding process by a plurality of molding apparatuses 1. Therefore, the equipment capacity of the molding apparatus 1 that performs each molding process can be a required load of the molding process with the largest load in each molding process, and the molding apparatus 1 can be downsized.

  Therefore, according to the molding method and the molding apparatus 1 of the cup-shaped part 8 of the present example, the cup-shaped part 8 having a stepped side wall shape with excellent strength and dimensional accuracy can be achieved while the molding equipment can be downsized. Can be molded.

Explanatory drawing which shows the shaping | molding method of a cup-shaped component in an Example. Sectional explanatory drawing which shows a cup-shaped component in an Example. The perspective explanatory view which shows the shaping | molding apparatus of the cup-shaped components before performing a preforming process in an Example. The perspective explanatory view which shows the shaping | molding apparatus of the cup-shaped components after performing the preforming process in an Example. The perspective explanatory view which shows the shaping | molding apparatus of the cup-shaped component after performing the intermediate shaping | molding process in an Example. The perspective explanatory view which shows the shaping | molding apparatus of the cup-shaped component after performing the finish shaping | molding process in an Example. Sectional explanatory drawing which shows the shaping | molding apparatus of the cup-shaped components before performing a preforming process in an Example. Cross-sectional explanatory drawing which shows the shaping | molding apparatus of the cup-shaped component after performing the preforming process in an Example. Cross-sectional explanatory drawing which shows the shaping | molding apparatus of the cup-shaped component after performing the intermediate shaping | molding process in an Example. Cross-sectional explanatory drawing which shows the shaping | molding apparatus of the cup-shaped components before performing a finish shaping | molding process in an Example. Cross-sectional explanatory drawing which shows the shaping | molding apparatus of the cup-shaped component after performing the finish shaping | molding process in an Example. Sectional explanatory drawing which expands and shows the principal part of the shaping | molding apparatus of the cup-shaped components before performing an intermediate shaping | molding process in an Example. It is a figure which shows the shaping | molding method of a cup-shaped component in a prior art example, (a) The state which formed the bottom face part and the preliminary | backup small diameter side wall part, (b) The state which formed the small diameter side wall part, (c) A level | step difference part and preliminary | backup large Explanatory drawing which shows the state which formed the diameter side wall part, the state which formed the cup-shaped component by forming the (d) large diameter side wall part.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Cup-shaped component shaping | molding apparatus 2 Dies 21 Molding hole 22 Die side tooth mold forming surface 3 1st punch 4 Punch core part 41 Flat pressure surface 5 Punch outer peripheral part 51 Stepped annular pressure surface 52 Punch side tooth mold forming surface 6 2nd Punch 61 Convex annular facing surface 8 Cup-shaped part 80A Flat plate material 80B Preliminary molded body 80C Intermediate molded body 81 Bottom surface portion 82 Small diameter side wall portion 83 Stepped portion 84 Large diameter side wall portion 85 Preliminary bottom surface portion 86 Preliminary inclined side wall portion 861 Base end side portion 862 Middle part 863 Tip side part 87 Preliminary large-diameter side wall part

Claims (6)

A bottom surface portion, an annular small-diameter side wall portion erected from the outer peripheral end portion of the bottom surface portion, an annular step portion formed outward from the end portion of the small-diameter side wall portion, and an outer peripheral end of the step portion In a method of molding a cup-shaped part having an annular large-diameter side wall portion erected from the portion,
Preliminary molding to obtain a preformed body by drawing a flat plate material, and forming a preliminary bottom surface portion having an outer diameter smaller than the bottom surface portion and a preliminary inclined side wall portion inclined in an annular manner from the preliminary bottom surface portion. Process,
Forming the preformed body, forming the bottom surface portion from the base end side portion of the preliminary inclined side wall portion and the preliminary bottom surface portion, and forming the preliminary large-diameter side wall portion from the distal end side portion of the preliminary inclined side wall portion. Forming and forming the small-diameter side wall portion and the stepped portion from an intermediate portion between the base end portion and the tip end portion to obtain an intermediate formed body; and
A cup-shaped part molding method comprising: a finish molding step of forming the large-diameter side wall part by ironing the preliminary large-diameter side wall part to obtain the cup-shaped part.   The cup-shaped part according to claim 1, wherein, in the finish molding step, the preliminary large-diameter side wall portion is ironed and tooth-shaped, and a tooth surface is formed on the large-diameter side wall portion. Molding method.   3. The method of molding a cup-shaped part according to claim 2, wherein the cup-shaped part is a clutch drum having a tooth surface on the large-diameter side wall. 4. When molding the cup-shaped part according to claim 1, a die provided with a molding hole, a first punch disposed to face each other so as to slide in the molding hole of the die, and While preparing the second punch, the first punch is divided and formed into a punch outer peripheral part and a punch core part located substantially in the center part,
The flat plate material is disposed between the first punch and the die and the second punch, the punch core portion in the first punch is advanced with respect to the die, and the preforming step is performed.
Next, maintaining the state where the preform is sandwiched between the punch core portion and the second punch, the punch outer peripheral portion of the first punch is advanced with respect to the die and the second punch, Perform the above intermediate molding process,
Next, maintaining the state where the intermediate molded body is sandwiched between the punch outer peripheral portion and the second punch, the punch outer peripheral portion and the second punch are advanced with respect to the die, and the finish forming step A method for forming a cup-shaped part, comprising: A bottom surface portion, an annular small-diameter side wall portion erected from the outer peripheral end portion of the bottom surface portion, an annular step portion formed outward from the end portion of the small-diameter side wall portion, and an outer peripheral end of the step portion In a molding apparatus for molding a cup-shaped part having an annular large-diameter side wall portion erected from the portion,
The molding apparatus includes a die having a molding hole, and a first punch and a second punch that are arranged to face each other so as to slide in the molding hole of the die.
The first punch is divided into a punch outer peripheral portion and a punch core portion positioned substantially at the center thereof, and the punch outer peripheral portion forms a part of the bottom surface portion, the small-diameter side wall portion, and the step portion. The punch core portion has a flat pressure surface for forming the remainder of the bottom surface portion, and the outer diameter of the flat pressure surface is outside the bottom surface portion. Smaller than the diameter,
The second punch has a convex annular facing surface having a shape along a shape when a part of the stepped annular pressure surface in the outer peripheral portion of the punch and the flat pressure surface in the punch core portion form substantially the same surface. Has
The molding apparatus advances the punch core portion in the first punch relative to the die, and then advances the punch outer peripheral portion in the first punch relative to the die and the second punch, and then An apparatus for molding a cup-shaped component, wherein the punch outer peripheral portion of the first punch and the second punch are advanced with respect to a die. In claim 5, a die side tooth mold forming surface for forming a tooth surface on the large-diameter side wall portion is formed on the inner wall surface of the forming hole in the die,
On the outer peripheral surface of the punch outer peripheral portion of the first punch, a punch side tooth mold forming surface for forming a tooth surface on the large diameter side wall portion is formed together with the die side tooth mold forming surface. An apparatus for forming cup-shaped parts.

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